Power semiconductor modules which are supplied with high currents and/or which provide high output currents are usually connected to a voltage supply or a load with the aid of low-impedance connecting conductors. For this purpose, the connecting conductors are screwed to corresponding connecting elements of the power semiconductor module.
The screw joint is often realized by the fact that an end of the connecting element that is accessible from the outer side of the module is led parallel to the housing wall and is provided with a hole in this region. Below the connecting element, a screw nut is placed behind the hole, the screw nut being inserted into a depression in the housing. The corresponding connections of the connecting conductor are likewise perforated and are screwed to the connecting element of the module by a screw, by virtue of the screw being screwed into the screw nut. For mounting purposes, therefore, firstly a screw nut must be inserted into a depression on the housing and the end of the connecting element that is provided with the hole must be bent across the inserted screw nut. Afterward, the hole in the connecting conductor must be positioned with accurate register above the hole in the connecting element, and a screw must be led through the two holes and screwed to the screw nut. It may also possibly be necessary to fit a washer in order to transmit the force from the screw uniformly to the connecting conductor. On account of the large number of processing steps, the mounting of the connecting conductor on the power semiconductor module is conventionally highly complex and thus cost-intensive.
Moreover, in the region of the screw joint, there is only a small contact zone between the connecting conductor and the connecting element, for which reason the location of the screw joint limits the current via the connecting element and the connecting conductor. The same correspondingly also applies to heat conduction, since the operating heat that arises in a power semiconductor module is, to a certain degree, also dissipated via its connecting elements and the connecting conductors connected thereto.